The primary goal of this Phase I project is to test the feasibility of a computerized diagnostic tool for collaborative assessment of psychiatric disorders in children and adolescents. Such a system is sorely needed in both clinical and research settings because (a) structured clinical interviews, although the gold standard in diagnosis, are time consuming and underutilized, and (b) the clinical judgment that is often substituted is of Limited accuracy and subject to several significant biases. Using the diagnostic rules from the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), the proposed product will provide clinicians with automated actuarial symptom and diagnostic data thereby circumventing these limitations while assisting the collaborative diagnostic process. These goals will be accomplished by integrating a reliable and valid symptom checklist filled out by patient informants with an advanced rule-based documentation system that employs an established logic-processing engine and which utilizes the complete DSM-IV rule set. Based on the presence and severity of discrete symptoms, clinicians will be provided with actuarially derived probability values that indicate the likelihood of specific DSM-IV criteria or disorders. Additionally, it will facilitate rapid and complete documentation DSM-IV criterion necessary to formally validate or refute diagnoses. The improved integration of client and clinician information will provide increased diagnostic precision and facilitate collaboration between providers and clients. In Phase II, the system will be extended to support repeated assessment, direct access via the World Wide Web, and larger sampling to collect further psychometric information. Phase I objectives include: 1. To produce a highly usable collaborative diagnostic assessment tool that will be used by individual practitioners, small group practices and their clients. 2. To automate the determination of the positive and negative predictive power of informant symptom data for corresponding DSM-IV criterion and diagnoses, and to collect an initial data set to evaluate usability and psychometric properties of the system. Phase II objectives include: (1) creation of a user interfaces and program logic to support repeated assessment (2) scaling to provide direct access via the World Wide Web and (3) larger sampling to extend the known psychometric properties of the system. PROPOSED COMMERCIAL APPLICATION: Commercial potential is present in several areas related to psychiatric diagnosis and clinical decision-making: clinical practice, enterprise decision support, training, education, research, medical records, and managed care.